<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    //原型上的也可以
    Object.prototype.a="a";
    var obj = {}
    
    var {toString:b,a} = obj;
    console.log(b,a);

</script>
</html>